Enter the price of the item in the Final Value field (the other final value fields will correspond the value fields set up on Main tab of the items screen, e.g. they may have been set up to reflect prices of different quantities of the item, this will not be the same in all items and may not be shown at all if not previously set up).

Click on the green tick button to save any changes.

When the Item is added to the contract/order line, if the contract/order is in the same currency as the alternative item rate, this rate will be selected.